That's pretty cool!
Thatcher being an ice hockey goaltender from San Diego definitely knows a thing or two about figuring it out on his own.
In the early 2000s when I was learning to play goal, things were starting to get far more technical very quickly. It really was a treat to come up at that time, when the position was evolving so rapidly. I was even asked by the PE teacher in middle school to run a "goalie clinic", just so that our school floor hockey games would be more competitive. The kids that I worked with ended up really enjoying playing goal, and were markedly improved for our games.
Everybody understands the basic concept of playing goal - you just block the net. But it's a very technical position, and learning how to find your own style while using proper technique can make things a lot more fun. As sad as it is, though - you do need to have a serious passion to be able to be "your own coach". Most kids won't get there without having some formal training early on to make things stick.